Sewing machine



Dec- 30, I J. A. GROEBL:

SEWINGMACHINE Filed Jan. 12 1924 Quinn U601,

Patented Dec. 30, 1924.

UNITED STATES JOSEPH A. GROEBLI, OF NEW YORK, N, Y.

SEWING MACHINE.

Application filed January 12, 1924. Serial No. 685,773.

To all whom it may concern:

Be it known that I, JosnrH A. Gnonnnr, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain new and useful. Improvements in Sewing Machines, of which the following is a specification.

My invention relates to loop stitch sewing machines; and its principal object is to automatically regulate the amount of thread which shall be drawn from a thread reel, so as to prevent both the accumulation of too much slack thread and the presence of too little, this regulating taking place, prefer ably, before the thread passes to the ordinary tensioning mechanism, so that the sup ply of thread to that tensioning mechanism and past it to the stitch forming mechanism 1 shall be even and uniform.

In the drawings I have illustrated my improvements as applied to a bead sewing ma chine. But it is to be understood that they are equally applicable whether or not beads are used.

In the drawings, Fig. 1 is a side elevation of part of the head and attachments of a sewing machine provided with my improvements, the bead separator and looper being, however, in section; Fig. 2 is a plan view, on an enlarged scale, of the thread reel and tensioning mechanism; Fig. 3 is an elevation of the same, taken as looking up on Fig. 2, an upper, operating gear being added; Fig. 4 1s a detail of the normal tensioning means, taken as looking. to the right on Fig. 3; and Fig. 5 is a cross sectional view of the tubes and thread channel, taken as looking up on Fig. 3.

In all the figures the same parts are marked with the same reference numerals.

A type of machine to which my improve ments may be applied is shown in my Letters Patent No. 1,445,764, of February 20, 1923-; and the details of the embodiment of my improved mechanism in such a machine will be readily understood when it is noted that tubes 38 and 53 of my present application correspond to the elements similarly numbered in my aforesaid patent, and are supported and actuated in a similar manner; that similar needle actuating mechanism may be employed; and that the bead thread may be supplied by means like those illustrated in said patent.

In operation the needle 1 produces, with the stitching thread 2, a loop stitch, the

stitching thread being around the bead thread 3 by the looper 4, during the formation of, the stitch, to attach that thread and its beads in proper position on the fabric. The looper 4 is carried by and revolves with the tube 38; while the bead separator shown is of the jawed type, and is adapted to release a head with each revolution of the separator. The details of construction of this separator are the subject of a separate application, Serial No. 651,769, filed July 16, 1923, so I will not describe them further herein.

The stitching thread reel 6 issupported by and also revolves with the tube 38, being connected therewith by a suitable bracket 7, upon which it is mounted over a spindle 8 on which it turns.

To the tube 53 is fastened a collar 9, carryinga cam 10, against which travels one end 11 of an arm 12 extending from a shaft 13 which is pivoted in bearings in a bracket l4'secured to a fitting 16 on the tube 38. The free end 15 of the arm 12 is pierced to allow the thread 2 to pass through it. The

preferably thrown arm 12' is kept to duty on the cam 10 by a against the fitting 16, but will be raised by cam 18 from such contact during the return swing of the arm 12.

The fitting 16 also carries a thread tensioning device embodying a support 21 to which is secured, as by screw 22, one end of a flat spring 23, the body and free end of which press against the support 21. This support 21 is pierced at two points, as 24, 25, and is provided with slots 26, 27 leading into the respective holes 24, 25; so that the thread 2 may be passed, conveniently between the spring 23 and support 21, and through the support into a hole 28 leading through the fitting 16 and tube 38 into the thread duct 29 inside of the tube 38. Through this duct the thread travels down to the stitch forming mechanism.

' The operation of the mechanism is as follows The thread 2 is carried, as shown, from the reel 6, through the guides,.the end of the arm 12, back through the guide 5, through hole 17 in bracket 14, under springs 19 and 28, through hole 28 and down through duct 29 to the needle.

WVhen the downward pull upon the thread, incident to the formation of the stitch, is relaxed, the rotation of the cam 18 allows'the spring 19 to close against the fitting 16, gripping and holding the thread 2 beneath the spring. The cam 10 then rocks the arm 12, throwing its extremity outward and thereby unrolling the thread 2 off of the reel 6, the amount of thread unreeled depending upon the amount of slack that may lie between the spring 19 and the reel 6 when the arm 12 begins its outward movement, for thereel' will not begin to unwind the thread until the slack has been'taken up by the'arm 12.

. After the arm 12 has completed its outward swing the cam 18 will raise the spring 19 and permit the thread to be drawn past the tension spring 23, by the drag of the stitch forming mechanism, the slack between the tension spring 23 and the reel 6 being taken up to a greater or less extent according'to the requirement of the particular stitch that is being formed. I

In a similar way thread is drawn off the reel for each succeeding stitch, the play of the arm 12 insuring the accumulation of a standard, maximum amount of slack thread ready for the formation of each stitch before it is required, and the replenishment of such part of the slack as has trative and not exclusive. T For it is tobe understood that details .may be modified,

as by the use of equivalents and the like, without departing from the scope of my invention as described and claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States, is

1. The combination, in a sewing machine, embodying stitch forming means including a looper, of a thread reel rotating, with the looper, tensioning 'means, means for creating slack thread between'the reel and the tensioning means and for restoring to the slack after each stitch an amount of "thread equal to that used in the preceding stitch. V V v 2. The combination, in'a sewmg machine, embodying stitch forming means lncluding 'a looper and looper" rotating means, of]

a thread reel carried by the rotating means, means for clamping the thread during part of each stitch cycle; means for simultaneously unreeling an amount of thread equal to that used for the preceding stitch, and

clamp releasing means. V

3. The combination, in a sewmg machine, embodying stitch forming means lncluding a looper, and looper rotating means, of a thread reel and a thread clamp carried by the rotating means, intermittently acting V unreeling means, and means for releasing the thread. clamp recurringly during the inaction of the unreeling means. 7

' 4. The combination, in asewing machine, embodying stitch forming means including a looper, and looper rotating means, of a thread reel and a thread clamp carried by the rotating means, intermittently acting unreeling means embodyinga camand an arm rocked thereby, and means for releasing the thread clamp recurringly during the inaction of the unreeling means.

' 5. The combination, in a sewing machine, embodying stitch forming means including a looper, and looper rotating means, of a thread reel and a thread clamp carried by the rotating means, intermittently acting unreelingineans embodying a cam and an arm rocked thereby, and means embodying a cam for releasing the thread clamp recurringly during the inaction of the unreeling means.

JOSEPH A. GROEBLI. 

